JP2007022918A - Method for producing 2-alkyl-2-adamantyl acrylates - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for simply obtaining 2-alkyl-2-adamantyl acrylates in higher yield. <P>SOLUTION: 2-Adamantanones and a halogenated hydrocarbon are reacted with a rod-like, spherical or massive metal lithium having 0.5-5,000 cm<SP>3</SP>size to synthesize a lithium (2-alkyl-2-adamantyl alkoxide) and excessive metal lithium remaining in the reactive system is removed and then, the resultant lithium (2-alkyl-2-adamantyl alkoxide) is reacted with acrylates or acrylic anhydrides to provide the 2-alkyl-2-adamantyl acrylates. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing adamantyl acrylates which are attracting attention as various resist raw materials for excimer lasers such as KrF and ArF, F2, X-rays, electron beams, EUV (extreme ultraviolet light), and high-functional polymer raw materials. Is.

  The 2-alkyl-2-adamantyl (meth) acrylates generally use a 2-adamantanone derivative as a Grignard reagent, or a 2-adamantanone derivative having a portion corresponding to the ester structure as a starting material. It is converted into a 2-alkyl-2-adamantanol derivative by reacting with an alkyl Li reagent, and the 2-alkyl-2-adamantanol derivative is isolated and then reacted with a (meth) acrylic acid derivative. It was. In this method, since the 2-alkyl-2-adamantanol derivative is once isolated, the process is long, and 2-alkyl-2-adamantyl (meth) acrylates are produced at low cost by a simple method. There have been many studies on how to do this.

  When producing 2-alkyl-2-adamantyl (meth) acrylates, (meth) acrylic acid halide is directly reacted with the 2-alkyl-2-adamantyl alkoxide derivative produced by the reaction of 2-adamantanone and an organometallic compound. There is also a method of obtaining the desired product without isolating the 2-alkyl-2-adamantanol derivative (Patent Document 1).

  Further, 2-adamantanone and a halogenated hydrocarbon are dissolved or suspended in a solvent, and this solution is reacted with metallic lithium to obtain lithium (2-alkyl-2-adamantyl alkoxide). There is also a method of reacting by adding an acrylic acid halide or the like (Patent Document 2). However, when (meth) acrylic acid halide is used as an esterification reagent, there are many by-products that are difficult to remove, and there are problems such as polymerization and decomposition during distillation purification due to these by-products.

  Further, after reacting 2-adamantanone with an organometallic compound such as alkyllithium or alkylmagnesium halide, the produced 2-alkyl-2-adamantylalkoxide derivative and (meth) acrylic acid ester or (meth) acrylic anhydride There is also a method of producing 2-alkyl-2-adamantyl (meth) acrylates by reacting (Patent Document 3). In this method, 2-alkyl-2-adamantyl (meth) acrylates can be obtained with a high yield and can be purified by distillation without causing polymerization or decomposition. However, since it is necessary to prepare alkyl lithium and alkyl magnesium halides, it is a method that is not easy to produce industrially.

  Further, 2-adamantanone and a halogenated hydrocarbon are dissolved or suspended in a solvent, and this solution is reacted with metallic lithium to obtain lithium (2-alkyl-2-adamantyl alkoxide). There is a method of producing 2-alkyl-2-adamantyl (meth) acrylates by reacting a (meth) acrylic acid ester or (meth) acrylic anhydride (Patent Document 4). In this method, 2-alkyl-2-adamantyl (meth) acrylates can be obtained with a high yield without preparing an organometallic compound, but because metallic lithium in a fine particle state that is rich in reactivity is used, Separation of lithium (2-alkyl-2-adamantyl alkoxide) and excess metallic lithium is difficult. For this reason, there exists a problem that there are many polymers by side reaction with metal lithium and (meth) acrylic acid esters or (meth) acrylic anhydrides in an esterification reaction process.

Japanese Patent Laid-Open No. 10-182552 International Publication No. 01/87817 Pamphlet JP 2002-241342 A JP 2004-315464 A

  The object of the present invention is to react from a 2-alkyl-2-adamantyl alkoxide solution, which is a reaction intermediate, in the synthesis of 2-alkyl-2-adamantyl (meth) acrylates from 2-adamantanones using metallic lithium. It is an object of the present invention to provide a method capable of reducing the amount of polymer produced as a by-product during the esterification reaction by removing excess metal lithium remaining in the system, and producing efficiently and inexpensively.

As a result of intensive studies on the above-mentioned problems, the present inventors have used metal lithium in the form of rods, spheres, or lumps of 0.5 to 5000 cm ³ , so that metal lithium, 2-adamantanone, and halogenated carbonization are used. After the reaction with hydrogen, the excess lithium metal remaining in the reaction system is removed from the resulting lithium (2-alkyl-2-adamantyl alkoxide solution) and reacted with an acrylate ester or an acrylate anhydride. The inventors have found that 2-alkyl-2-adamantyl acrylates can be efficiently produced, and have reached the present invention.

That is, in the present invention, a 2-adamantanone represented by the formula (1) and a halogenated hydrocarbon represented by the formula (2) are reacted with metallic lithium, and lithium (2-alkyl) represented by the formula (3) is obtained. -2-adamantyl alkoxide), the excess metal lithium remaining in the reaction system is removed, and then the resulting lithium (2-alkyl-2-adamantyl alkoxide) and the acrylate ester represented by formula (4) In the method for producing 2-alkyl-2-adamantyl acrylates represented by the formula (6) by reacting the carboxylic acid anhydrides or acrylic anhydrides represented by the formula (5), the lithium metal used in the reaction is 0 A method for producing 2-alkyl-2-adamantyl acrylate, characterized in that it is in the form of a rod, sphere or lump of 5 to 5000 cm ^3. It is related.

（式中、Ｙは同一でも異なってもよく、水素原子、炭素数１〜１０のアルキル基、炭素数 １〜１０のハロゲン含有アルキル基、ハロゲン原子を示し、ｎは１〜１４の整数を示す。）

(Wherein Y may be the same or different and represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a halogen-containing alkyl group having 1 to 10 carbon atoms, or a halogen atom, and n represents an integer of 1 to 14) .)

（式中、Ｒ_１は炭素数１〜１０の炭化水素基、Ｘはハロゲン原子を示す。）

(In the formula, R ₁ represents a hydrocarbon group having 1 to 10 carbon atoms, and X represents a halogen atom.)

（式中、Ｒ₁、Ｙ及びｎは前記と同様。）

(Wherein R ₁ , Y and n are the same as described above.)

（式中、Ｒ_２〜Ｒ₄は水素原子、ハロゲン原子、炭素数１〜６のアルキル基、又は炭素数１〜６のハロゲン含有アルキル基を示す。Ｒ₅は炭素数１〜６のアルキル基を示す。）

(In the formula, R _{2 to} R ₄ represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen-containing alkyl group having 1 to 6 carbon atoms. R ₅ represents an alkyl group having 1 to 6 carbon atoms. Is shown.)

（式中、Ｒ_２〜Ｒ₄は前記と同様。）

(Wherein R _{2 to} R ₄ are the same as described above.)

（式中、Ｒ₁〜Ｒ₄、Ｙ及びｎは前記と同様。）

(Wherein R _{1 to} R ₄ , Y and n are the same as described above.)

  According to the present invention, 2-alkyl-2-adamantyl acrylates can be obtained in a simple and higher yield.

  The 2-adamantanones (2-adamantanone and its derivatives) that are raw materials of the present invention are represented by the following formula (1).

  In the formula, Y represents a hydrogen atom, an alkyl group, a halogen-containing alkyl group, or a halogen atom. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, or a pentyl group. Examples of the halogen-containing alkyl group include those having 1 to 10 carbon atoms such as a trifluoromethyl group. Examples of the halogen atom include fluorine, chlorine, bromine and iodine. n shows the integer of 1-14. When a plurality of Y are present, these may be the same or different.

R ₁ in Formula (2) is a hydrocarbon group, preferably an aliphatic, alicyclic or aromatic hydrocarbon group having 1 to 10 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, It is a butyl group. X is exemplified by chlorine, bromine and iodine as halogen. Specific compounds include methyl bromide, ethyl bromide, propyl bromide, butyl bromide, methyl iodide, ethyl iodide, propyl iodide, butyl iodide, methyl chloride, ethyl chloride, propyl chloride, and butyl chloride. Can be mentioned.

  The halogenated hydrocarbon compound is used in an amount in the range of 1 to 5 equivalents, preferably 1.0 to 1.6 equivalents relative to the starting 2-adamantanone. When the amount used is large, the excess amount of the alkyllithium reagent produced by contact between the halogenated hydrocarbon compound and metallic lithium increases by-products due to reaction with solvents, acrylic esters, and acrylic anhydrides. This is to make it happen.

  The usage-amount of metallic lithium is 1.5-5.0 equivalent with respect to 2-adamantanone, Preferably it is 2.0-3.0 equivalent. If the amount is smaller than this, the conversion of 2-adamantanone is insufficient, and if the amount is larger, it is uneconomical.

  The temperature in the reaction with 2-adamantanones, halogenated hydrocarbon compounds and metallic lithium is -30 to 100 ° C, preferably 0 to 50 ° C. When the temperature is lower than −30 ° C., the reaction rate decreases, and when the temperature is higher than 100 ° C., it becomes difficult to control the reaction or a side reaction proceeds to decrease the yield. Moreover, you may change within the range of -30 degreeC-100 degreeC by operation, such as a heating or cooling, during reaction.

  In the case of using highly reactive metal lithium such as fine particles, granules, and wires, the metal lithium remaining after the alkylation reaction is fine. Since the precipitation of lithium (2-alkyl-2-adamantyl alkoxide) and lithium halide produced together with the alkylation reaction is also fine, in solid-liquid separation using a filter, lithium (2-alkyl-2-adamantyl alkoxide) and lithium Lithium halide is also separated.

Therefore, if the metallic lithium remaining after the alkylation reaction is different in size from the lithium (2-alkyl-2-adamantyl alkoxide) and lithium halide precipitates produced, The remaining lithium can be physically removed. The shape of the metallic lithium to be used, it is preferred to use rod-like 0.5～5000Cm ^3, spherical, those massive. More preferably from 1.0~500cm ^3. When metal lithium smaller than this is used, the surface area per weight increases and the reaction rate increases, but the size of the remaining metal lithium after the reaction is lithium (2-alkyl-2-adamantyl alkoxide) and halogenated. It approaches the size of the lithium precipitate, making it difficult to remove. When metal lithium larger than this is used, it is easy to remove the remaining lithium after the reaction, but since the surface area per unit weight is small, the reaction rate becomes slow and the reaction efficiency becomes poor. Furthermore, even when metallic lithium having a size within the above range is used, it is not preferable when wire-like metallic lithium or the like is used because removal of residual lithium becomes difficult.

  This reaction is usually performed in the presence of a solvent, but can also be performed in the absence. Examples of the solvent include ethers such as tetrahydrofuran and diethyl ether, aliphatic hydrocarbon compounds such as hexane, heptane, and cyclohexane, and aromatic hydrocarbon compounds such as benzene, toluene, and cumene. However, it is not limited to them. The amount of the solvent used is preferably 1 to 50 mL with respect to 1 g of 2-adamantanone. When using a solvent, it is not necessary to completely dissolve the raw materials and the like as long as they do not greatly affect stirring and the like. Further, the reaction solution may be dissolved or become a slurry as the reaction proceeds. In the present invention, the definition of the solution includes a slurry form.

  There is no restriction | limiting in particular in the mixing method with 2-adamantanone, a halogenated hydrocarbon compound, and metallic lithium. The 2-adamantanone and the halogenated hydrocarbon compound may be dissolved in a solvent, and metallic lithium may be added. Further, 2-adamantanones may be added after the halogenated hydrocarbon compound and metallic lithium are reacted in a solvent first. The addition method may be batch addition or sequential addition or both, and the addition rate is not particularly limited, but it is usually preferred to add at a rate that does not cause an abnormal temperature rise in the reaction temperature.

  The method for removing metallic lithium after the alkylation reaction is not particularly limited. For example, there is a method in which the reaction solution is passed through a screen having a pore diameter of about several millimeters, and because of the low specific gravity of Li, it is removed by decantation. In the laboratory, the remaining lithium may be removed with a forceps and removed from the reaction solution more easily.

  Reaction with 2-adamantanones, halogenated hydrocarbon compounds, and metallic lithium produces lithium (2-alkyl-2-adamantyl alkoxide) as a reaction intermediate. In the present invention, it is preferable to carry out a reaction (esterification reaction) in which acrylic esters or acrylic anhydrides are added to the reaction system without separating the reaction intermediate.

  Acrylic acid esters are represented by the following formula (4).

In Formula (4), R _{2 to} R ₄ represent a hydrogen atom, a halogen atom, an alkyl group, or a haloalkyl group. As an alkyl group, it is a C1-C6 alkyl group like a methyl group and an ethyl group. Examples of halogen include fluorine, chlorine and bromine. The haloalkyl group is a partially or fully halogenated alkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group. Preferably, they are a hydrogen atom, a fluorine atom, a methyl group, and a trifluoromethyl group. R ₅ is an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group. Specific examples of acrylic esters include methyl acrylate, ethyl acrylate, isopropyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, methyl trifluoroacrylate, ethyl trifluoroacrylate, and trifluoroacrylic acid. Isopropyl, trifluoroacrylate-t-butyl, pentafluoromethyl methacrylate, pentafluoroethyl methacrylate, pentafluoroisopropyl methacrylate, pentafluoromethacrylate-t-butyl, methyl 2-fluoroacrylate, 2-fluoroacrylic acid Ethyl, isopropyl 2-fluoroacrylate, 2-tert-butyl 2-fluoroacrylate, methyl 2- (trifluoromethyl) acrylate, 2- (trifluoromethyl) ethyl acrylate, 2- (trifluoromethyl) isopropyl acrylate, 2- (trifluoromethyl) include butyl -t- acrylate.

  The amount of the acrylate compound added is 1 to 20 equivalents, preferably 1 to 5 equivalents, relative to the starting 2-adamantanone. When the amount is less than 1 equivalent, the yield decreases. When the amount is more than 20 equivalents, the efficiency of the kettle decreases and purification becomes difficult.

  Acrylic anhydrides are represented by the following formula (5).

In Formula (5), R _{2 to} R ₄ represent a hydrogen atom, a halogen atom, an alkyl group, or a haloalkyl group. As an alkyl group, it is a C1-C6 alkyl group like a methyl group and an ethyl group. The halogen group is fluorine, chlorine or bromine. The haloalkyl group is a partially or fully halogenated alkyl group having 1 to 6 carbon atoms such as a trifluoromethyl group. Preferably, they are a hydrogen atom, a fluorine atom, a methyl group, and a trifluoromethyl group.

  The amount of acrylic anhydride added is 0.5 to 10 equivalents, preferably 0.5 to 3 equivalents, relative to the starting 2-adamantanone. When the amount is less than 0.5 equivalent, the yield decreases. When the amount is more than 10 equivalent, the efficiency of the kettle decreases and purification becomes difficult.

  When adding acrylic acid esters or acrylic acid anhydrides (hereinafter collectively referred to as esterifying agents), the addition method and the addition speed are not particularly limited, but usually the raw material 2-adamantanone is a reaction intermediate. After sufficient conversion to some lithium (2-alkyl-2-adamantyl alkoxide), it is preferable to add the esterifying agent after the conversion has reached at least 80 mol%.

  The reaction temperature for esterification is −50 ° C. to 200 ° C., preferably 0 ° C. to 100 ° C. When the temperature is lower than −50 ° C., the reaction rate decreases, and when the temperature is higher than 200 ° C., it becomes difficult to control the reaction or side reaction proceeds to decrease the yield. Moreover, the reaction temperature at the time of synthesis of lithium (2-alkyl-2-adamantyl alkoxide) and the subsequent reaction time and the reaction temperature at the time of addition of the esterifying agent and the subsequent reaction time may be the same or different. You may change within the range of -70 to 200 degreeC by operation.

  The reaction time for esterification is preferably 0.5 to 1000 hours. More preferably, 1 to 100 hours are required. The reaction time depends on the reaction temperature and is determined according to the desired yield and the like, and is not limited to the above range.

Regarding adamantyl acrylates used in the present invention, R ₁ in formula (6) corresponds to R ₁ of the alkyl halide compound of formula (2). Further, R ₂ to R ₄ in the formula (6) is, R ₂ to R ₄ acrylic esters of the formula (4), and corresponds to R ₂ to R ₄ acrylic acid anhydrides of the formula (5) ing.

  In the present invention, the desired 2-alkyl-2-adamantyl (meth) acrylates can be obtained with a sufficiently high reaction yield even under the above conditions. By adding a polymerization inhibitor during the reaction, polymerization of the esterifying agent is performed. By-products can be suppressed. In particular, 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl, N-nitrosophenylhydroxylamine ammonium salt, N-nitrosophenylhydroxylamine aluminum salt, N-nitroso-N- (1-naphthyl) ) The polymerization inhibitory effect of hydroxylamine ammonium salt, N-nitrosodiphenylamine, and N-nitroso-N-methylaniline is high.

  In addition to the above-mentioned polymerization inhibitor, there may be a case where the effect is further enhanced when another polymerization inhibitor is allowed to coexist. Such polymerization inhibitors include nitrosonaphthol, p-nitrosophenol, nitroso compounds such as N, N'-dimethyl-p-nitrosoaniline, sulfur-containing compounds such as phenothiazine, methylene blue, 2-mercaptobenzimidazole, N, N '-Diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, 4-hydroxydiphenylamine, amines such as aminophenol, hydroxyquinoline, hydroquinone, methylhydroquinone, p-benzoquinone, hydroquinone monomethyl ether Quinones such as methoxyphenol, 2,4-dimethyl-6-t-butylphenol, catechol, 3-s-butylcatechol, 2,2-methylenebis- (6-t-butyl-4-methylphenol) Phenols such as, imides such as N- hydroxyphthalimide, cyclohexane oximes, oxime such as p- quinone dioxime, and the like dialkyl thiodipropionate Pineto acids. On the other hand, even when these polymerization inhibitors are used alone, the polymerization inhibition effect is hardly observed.

  The amount of the polymerization inhibitor to be added is 0.00001 to 0.1 parts by weight, preferably 0.0001 to 0.02 parts by weight, based on the esterifying agent. If it is less than that, the polymerization inhibiting effect does not appear, and if it is more than that, the polymerization inhibiting effect is not improved.

  The addition method and addition rate of the polymerization inhibitor are not particularly limited. For example, the dialkylmagnesium and / or metal alkoxides may be preliminarily charged into the reaction solution, but are usually added at the same time, or immediately before or after the esterifying agent is added. Is desirable. As an addition method, the polymerization inhibitor may be dissolved in an esterifying agent and added, or a polymerization inhibitor may be added separately from the esterifying agent. At the time of addition, it may be dissolved in a solvent or may be added as it is.

  After completion of the reaction, the salt derived from alkyl lithium and / or metal alkoxide is removed by washing the reaction solution with water. At this time, the washing water may contain an appropriate inorganic salt such as sodium chloride or sodium bicarbonate. Further, the unreacted esterifying agent is removed by alkali washing. Examples of the alkali component include a sodium hydroxide aqueous solution, a potassium hydroxide solution, and aqueous ammonia, but the alkali component to be used is not particularly limited. In addition, acid cleaning may be performed to remove metal impurities. Examples of the acid component include inorganic acids such as hydrochloric acid aqueous solution, sulfuric acid aqueous solution, and phosphoric acid aqueous solution, and organic acids such as oxalic acid aqueous solution, but the acid component used is not particularly limited.

  Further, when washing, an organic solvent may be added to the reaction solution according to the physical properties of the produced adamantyl acrylates. The organic solvent to be added may be the same as that used in the reaction or may be different, but it is usually desirable to use a solvent with a low polarity that is easily separated from water. The adamantyl acrylates thus obtained are separated and purified from the organic layer by known methods such as distillation, concentration, filtration, crystallization, recrystallization and column chromatography.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

Example 1
After replacing the 1 L three-necked flask equipped with a stirrer with argon, 5.8 g of lithium rod (1 cmΦ × 5 cm: 3.9 cm ³ ) (2.5 molar equivalent to 50 g of 2-adamantanone) and 120 ml of hexane was charged to 20 ° C. Separately, 50 g of 2-adamantanone and then 167 ml of tetrahydrofuran and 51 g of ethyl bromide (1.4 molar equivalents relative to 50 g of 2-adamantanone) were added to a 500 ml two-necked flask under an argon atmosphere and dissolved uniformly. Subsequently, a tetrahydrofuran solution of 2-adamantanone and ethyl bromide was dropped into a 1 L three-necked flask (lithium rod / hexane). At this time, the dropping rate and the cooling temperature were adjusted so that the temperature in the flask would not be 40 ° C. or higher. After completion of the dropwise addition, the mixture is aged for a while, and 2-adamantanone is found to be 98% or more in lithium 2-ethyl-2-adamantyl alkoxide (detected as 2-ethyl-2-adamantanol on the gas chromatograph) by gas chromatographic analysis. It was confirmed that it was converted. After confirmation, the metallic lithium remaining in the reaction system was removed with tweezers (the weight of the removed metallic lithium was 0.3 g).

Next, 200 ml of tetrahydrofuran and 100 g of methyl methacrylate (3.0 molar equivalents with respect to 50 g of 2-adamantanone) were added to the three-necked flask and reacted at a reaction temperature of 65 ° C. for 9 hours. After completion of the reaction, 100 ml of hexane was added to the reaction solution, 150 ml of pure water was further added, and the mixture was sufficiently stirred. The reaction solution was separated, and the organic layer was washed once with 100 g of 5% sulfuric acid and three times with 100 ml of pure water. The obtained organic layer was concentrated to remove the solvent and unreacted methyl methacrylate to obtain a crude product. This crude product was distilled under reduced pressure, and the obtained fraction was crystallized in acetonitrile. From GC-MS analysis and ¹ H-NMR analysis, 64 g (yield 78%) of high-purity 2-ethyl- 2-Adamantyl methacrylate was obtained.

Example 2
After a stainless steel reactor equipped with a stirrer 1L was replaced with argon, lithium rods into the reactor ^{(1cmΦ × 5cm: 3.9cm 3)} 5.8g (2.5 molar equivalents relative to 2-adamantanone 50 g) and 120 ml of tetrahydrofuran was charged to 20 ° C. Separately, 50 g of 2-adamantanone and then 200 ml of tetrahydrofuran were added to a 500 ml two-necked flask under an argon atmosphere and dissolved uniformly. Further, 44 g of methyl bromide was filled into a 200 ml container made of stainless steel, and an argon pressure was applied (the pressure in the container was 3.9 × 10 ⁵ Pa). Next, the inside of a 1 L stainless steel reactor (lithium rod / hexane) was pressurized with argon (the pressure inside the vessel was 2.9 × 10 ⁵ Pa), and a tetrahydrofuran solution of 2-adamantanone was planned in the reaction vessel. It was dripped using a jar pump. At the same time, methyl bromide was dropped into the reaction vessel using the pressure difference between the methyl bromide vessel and the reaction vessel. At this time, the dropping rate and the cooling temperature were adjusted so that the temperature in the flask would not be 40 ° C. or higher. After completion of the dropwise addition, after aging for a while, 2-adamantanone is 98% or more in lithium 2-methyl-2-adamantyl alkoxide (detected as 2-methyl-2-adamantanol on the gas chromatograph) by gas chromatographic analysis. It was confirmed that it was converted. After confirmation, the metallic lithium remaining in the reaction system was removed with tweezers (the weight of the removed metallic lithium was 0.2 g).

Next, 160 ml of tetrahydrofuran and 83 g of methyl methacrylate (2.5 molar equivalents relative to 50 g of 2-adamantanone) were added to a 1 L stainless steel reactor and reacted at a reaction temperature of 55 ° C. for 6 hours. After completion of the reaction, purification was performed in the same manner as in Example 1. As a result, 70 g (yield 90%) of pure 2-methyl-2-adamantyl methacrylate was obtained from GC-MS analysis and ¹ H-NMR analysis.

Example 3
The shape of the metal lithium to be used in the 1 cm × 1 cm × 1 cm cube (1 cm ³⁾ The reaction was performed in the same manner as in Example 1. After completion of the reaction, purification was conducted in the same manner as in Example 1. As a result, 66 g (yield 80%) of pure 2-ethyl-2-adamantyl methacrylate was obtained.

Example 4
The reaction was carried out in the same manner as in Example 1 except that the shape of the metal lithium used was a rod (1.27 cmΦ × 4 cm: 5.1 cm ³ ). After completion of the reaction, purification was conducted in the same manner as in Example 1. As a result, 62 g (yield 75%) of pure 2-ethyl-2-adamantyl methacrylate was obtained.

Comparative Example 1
When the reaction was carried out in the same manner as in Example 1 except that fine metal lithium (weight average particle diameter: 176 μm) was used, the metal lithium remaining after the alkylation reaction could not be removed.
After completion of the reaction, purification was conducted in the same manner as in Example 1. As a result, 57 g (yield 69%) of pure 2-ethyl-2-adamantyl methacrylate was obtained.

Claims (1)

Lithium (2-alkyl-2-adamantyl alkoxide) represented by the formula (3) is obtained by reacting the 2-adamantanone represented by the formula (1) and the halogenated hydrocarbon represented by the formula (2) with metallic lithium. Then, excess metal lithium remaining in the reaction system is removed, and then the obtained lithium (2-alkyl-2-adamantyl alkoxide) and the acrylate ester represented by the formula (4) or the formula (5) in by reacting acrylic acid anhydrides represented, a process for the preparation of 2-alkyl-2-adamantyl acrylate represented by the formula (6), the metal lithium used for the reaction is 0.5～5000Cm ³ A method for producing 2-alkyl-2-adamantyl acrylates, which is rod-shaped, spherical or massive.

(In the formula, Y may be the same or different, and represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a halogen-containing alkyl group having 1 to 10 carbon atoms, or a halogen atom, and n represents an integer of 1 to 14) .)

(In the formula, R ₁ represents a hydrocarbon group having 1 to 10 carbon atoms, and X represents a halogen atom.)

(Wherein R ₁ , Y and n are the same as described above.)

(In the formula, R _{2 to} R ₄ represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen-containing alkyl group having 1 to 6 carbon atoms. R ₅ represents an alkyl group having 1 to 6 carbon atoms. Is shown.)

(Wherein R _{2 to} R ₄ are the same as described above.)

(Wherein R _{1 to} R ₄ , Y and n are the same as described above.)